Photographic light-sensitive material and development process comprising a development accelerator

ABSTRACT

A photographic light-sensitive material wherein at least one silver halide emulsion layer and/or photographic layer adjacent thereto contains a compound represented by the formula:   R1 can be a one-five carbon atom alkyl group, a one-five carbon atom hydroxyalkyl group, a tetrafurfuryl group or a seven-12 carbon atom aralkyl group. R2 and R3 can be a hydrogen atom, a one-five carbon atom alkyl group or an atomic group capable of forming a ring via linkage with R2 and R3. Q can be a sulfur atom or an imino group. Further described is a method of photographic reproduction which comprises exposing a photographic light-sensitive material as described above and developing said exposed material with an infectious developer containing hydroquinone.

United States Patent Assignee Fumihiko Nishio Kanagawa;

Ilideo Kawano, Kanagawa; Mitsunori Sugiyama, Kanagawa; Takeo Sakai, Kanagawa; Osami Aki, Kawanishi-shi, Hyogo, all of Japan June 30, 1969 Oct. 26, l 97 1 Fuji Photo Film Co., Ltd.

Kanagawa, Japan June 29, 1968 Japan Inventors Appl. No. Filed Patented Priority PI-IOTOGRAPHIC LIGHT-SENSITIVE MATERIAL AND DEVELOPMENT PROCESS COMPRISING A DEVELOPMENT ACCELERATOR 17 Claims, No Drawings U.S. Cl 96/663, 96/76 Int. Cl G03c 5/26, G03c l/06 Field of Search 96/663, 63,

References Cited UNITED STATES PATENTS 2,404,774 7/1946 Dersch et al Primary Examiner-Norman G. Torchin Assistant Examiner-Alfonso T. Suro Pico Attorney-Sughrue, Rothwell, Mion, Zinn & MacPeak ABSTRACT: A photographic light-sensitive material wherein at least one silver halide emulsion layer and/or photographic layer adjacent thereto contains a compound represented by the formula:

PIIOTOGRAPHIC LIGHT-SENSITIV E MATERIAL AND DEVELOPMENT PROCESS COMPRISING A DEVELOPMENT ACCELERATOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photographic materials, and more particularly, to high contrast photographic silver halide emulsrons.

Description of the Prior Art It is well known that a photographic image of high edgegradient is obtained when some silver halide photographic light-sensitive materials are processed with a particular developer, a so-called infectious developer containing mainly hydroquinone with a small content of sulfite and having a high pH value. For example, refer to a publication by Yule, J .A.C. Fonnaldehyde-Hydroquinone Developers and Infectious Development J. Frank Inst. 1945 239 221. However, when certain particular ingredients or additives are contained in a silver halide emulsion, the developing speed in processing with an infectious developer is sometimes highly delayed. For example, a silver chlorobromide emulsion having a high content of silver bromide needs a longer developing time in order to obtain a definite contrast (compared with another silver chlorobromide emulsion having a lower content of silver bromide). Further, the addition of polyalkylene oxide derivatives, well-known as coating agents, results in a remarkable decrease in the rate of infectious development. Therefore, it is important, in the case of employing an infectious developer of this kind, to accelerate the development and to shorten the time necessary for attaining a definite density or contrast.

SUMMARY OF THE INVENTION The first aspect of the present invention provides an improved light-sensitive photographic material which results in rapid development utilizing an infectious developer. The photographic light-sensitive material basically comprises a support having coated thereon at least one silver halide emulsion layer or at least one silver halide emulsion layer and a photographic layer adjacent thereto containing a compound represented by the following formula:

wherein R is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalkyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, R, and R each is a member selected from the group consisting of a hydrogen atom, an alkyl group having one to five carbon atoms and an atomic group capable of forming a ring through linkage with R and R and Q is a member selected from the group consisting of a sulfur atom and an imino group.

The present invention further comprises a method of photographic reproduction comprising exposing a photographic light-sensitive material as described above, and subsequently developing the exposed photographic material with an infectious developer containing hydroquinone.

It is an object of the invention to provide a silver halide emulsion which exhibits a high contrast in a relatively short developing time using an infectious developer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The above-mentioned object can be accomplished by adding to at least one of a silver halide emulsion layer and a layer adjacent thereto a compound represented by the following general formula:

Compound Is-Benzylsulfenyldithiocarboxydimethylamine Q-om-s-s-o-m M.P. 9698 C.

Compound IIN-(s-benzylsulfonyldithioearboxy) piperidine CH,CH;

Compound III-l-chlorophcnyl-4-(s-bcnzylsulfonyldtthiocarboxy) piperazine S Cur-CH1 M.P. 116-117 0.

Compound IV-s-4-isopropylbenzylsulfenyldithiocarboxymorpholine Compound V-N-(s-fl-hydroxyethylsulfenyldithiocarboxy) morpholine Compound VI-N-(s-t-butylsulfenyldithiocarboxy) piperidine Compound VII-N-(s-t-butylsulfenyldithiocarboxy) morpholine CHg- Cg; (CHahC-S-S-C-N 0 M.P. 6365 C.

Compound VIII-s-Benzylsulfenylisothiourea hydro- Compound IX-s-Furfurylsulfenylisothiourea hydro- M.P. 123125 C.

Compound Xs-4-isopropylbenzylsulfenylisothiourea hydrochloride CH3 NH M.P. 154-155 C.

Compound XIs-/3-hydroxyethylsulfenylisothiourea hydrochloride HO CH:CH;SS-C-NH2.HCI

M.P. 106-107 C.

Preparation of these compounds, for example, compound X and compound IV is carried out according to the following procedures, but is not intended to be limited thereby.

SYNTHESIS EXAMPLE A mixture of 2.4 g. of p-isopropylbenzyl chloride, 32.6 g. of thiourea and 99 percent of ethanol was boiled for 3 hours and concentrated to dryness. A solution of 100 g. of caustic soda in 400 ml. of water was added thereto and the mixture was boiled for 3 hours while bubbling nitrogen gas therein. After cooling and acidifying with hydrochloric acid, the mixture was extracted with about 1 l. of ethyl acetate, washed with water and dehydrated. Thereafter, the ethyl acetate was distilled off and the residue was fractionated to give 64 g. (yield 90 percent) of p-isopropylbenzylmercaptan melting at 1l6-l 17.5 C

A mixture of g. of p-isopropylbenzlymercaptan, 5.5 g. of thiourea, 9 ml. of concentrated hydrochloric acid, 9 ml. of water and 130 ml. of ethanol was stirred while cooling with ice (held at 5l0 C.) 7.5 g. of 30 percent hydrogen peroxide was added dropwise thereto. After the dropping addition, the mixture was further stirred for 3 hours, filtered and washed adequately with ethanol. The filtrate and washing solution collected were concentrated under reduced pressure to dryness. Ethanol was added thereto, warmed and the soluble matter separated, to which ether was then added to deposit a crystal. Recrystallization by the mixed solvent of ethanol and ether was repeated to obtain 1 1.7 g. (yield 70 percent) of s-4- isopropylbenzylsulfenylisothiourea hydrochloride (Compound X) melting at l54l55 C.

2.0 g. of potassium morphoiine dithiocarbamate was dissolved in 20 ml. of a 5 percent solution of sodium bicarbonate and, while stirring vigorously and cooling with ice, mixed with LII a solution of 2.8 g. of p-isopropylbenzylsulfenylisothiourea hydrochloride in 30 ml. of 50 percent ethanol. Immediately, the mixture was white turbid, viscous and hard to stir. The reaction mixture was allowed to stand for a short period of time, filtered and recrystallized from methanol to obtain 2.5 g. (yield 77 percent) of compound IV melting at 798l C. An elementary analysis of compound IV gave the following result:

H c s Calculated c,,|-i,,Nos, 6.46 55.00 29.37 Found 6.40 55.17 28.58

The amounts of the compounds added to the photographic emulsion varies according to the type of emulsion and compound. In general, it is preferable to add in a proportion of 0.05 to 10 g. of compounds to l mole of silver halide contained in the photographic emulsion.

Preparation of a photographic emulsion is generally carried out by three steps, that is to say, (1) precipitation and digestion of silver halide, i.e., physical digestion, (2) removal of excess salts by washing with water and (3) chemical digestion, i.e., after ripening, to increase the sensitivity. The compounds of the invention may be added to the emulsion at any state, but the best results can be obtained when added after the chemical digestion and before coating. The compounds are dissolved in solvents that have no determinal effect on the emulsion, for example, water, a lower alcohol such as methanol or ethanol, ketones such as acetone, and are added to the emulsion. These chemicals are ordinarily added directly to the emulsion, but if desired, they may be added to a photographic layer adjacent thereto, such as protective layer, to permeate therethrough to the emulsion layer.

The photographic emulsions that can be employed in this invention are ones such as silver chloride, silver bromide, silver chlorobromide, silver iodobromide and silver chloroiodobromide. Furthermore, a direct reversal emulsion, such as the Herschel effect or the solarization type, may be used.

The emulsion may be chemically sensitized by the wellknown art methods using one or more unstable sulfur-containing compounds such as ammonium thiosulfate and arylthiourea (Cf. P. Glafkides "Chemie Photographique" ll-Ed., p. 297-299 (1957)), and gold compounds such as a complex of monovalent gold and thiocyanic acid (cf. ibid., p. 301 The emulsion also may be optically sensitized by the addition of a sensitizing dye,such as cyanine dyes or merocyanine dyed (cf. Shinichi Kikuchi, Kagaku Shashin Binran (Handbook of Scientific Photography, p. 15-24 (Published by Maruzen C0., 1959). Moreover, the 1959). may be stabilized by the addition of heterocyclic compounds such as benzotriazole or 2- phenyl-S-mercaptotetrazole. In addition, the emulsion may be hardened by hardeners such as formaldehyde or mucochloric acid, and may contain surface active materials, such as saponin, so as to make coating easy.

A film designed so as to obtain a particularly high contrast by development using an infectious developer is known as a lithographic film. These light-sensitive materials of the lithtype consist generally of a silver chlorobromide emulsion having a high content of silver chloride, and are suitable for making the production of half tone dots by means of a glass screen or a contact screen.

When the compounds of the invention are added to the emulsion of the above-identified lithographic film, exposed to a halftone image and developed with the infectious developer, the developing time required for the product of halftone dots of high density is shortened and, accordingly, the optimum range of developing time, that is development latitude, is enlarged. Consequently, over a broader development time range, optimum dot quality is obtained.

The following examples are given in order to illustrate the invention, without limiting the same.

EXAMPLES To a silver chlorobromide emulsion containing 30 mol percent of silver bromide and optically sensitized with merocyanine dyes, the heretofore identified compounds were added in the following proportion. The resulting emulsions were coated onto a film base, dried, and the following sensitometry was carried out.

ln sensitometry, the films were exposed for l seconds through a stepwise optical wedge having a step difference of 0.1 by the use of a tungsten lamp (2666 K) as a light source, and then developed in a developer of the following composikyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, and Q is a member selected from the group consisting of a sulfur atom and an imino group.

tron: 5. The hoto ra hic li ht-sensitive material as claimed in P g P g claim 4 an amount of said compound is 0.05 g. to g. per 1 wan,In mm 500m, mol. of silver halide. Anhydrous sodium sulfite 30g. 6. A photographic light-sensitive material comprising a supi'mffmmldehyde 8' port having coated thereon at least one silver halide emulsion 22:? b'sulfim 10 layer and a photographic layer adjacent thereto containing a Hydmquinone :2 compound represented by the following formula, Potassium bromide 1.6 g. Water to make l liter /R2 R1SSCN The results obtained when the development was carried out at C for 2, 3 and 4 minutes are listed below.

Relative sensitivity Gamma Fog Compound Sample Number Number 2' 3' 4 2 3 4 2' 3 4 It will be apparent from these results that the addition of the compounds of the present invention results in a remarkable increase in the sensitivity at a developing time of 2 minutes, but has little effect at a developing time of 4 minutes. That is to say, the addition of the compounds of the invention results in an increase in the initial rate of development.

Whatis claimed is:

1. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer containing a compound or salt thereof represented by the following formula,

R2 R1-S-S?-N Q wherein R, is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalkyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, R, and R, each is a member selected from the group consisting of a hydrogen atom, an alkyl group having one to five carbon atoms and an atomic group capable of forming a ring through linkage with R and R and Q is a member selected from the group consistingof a sulfur atom and an imino group.

2. The photographic light-sensitive material as claimed in claim 1 wherein an amount of said compound is 0.05 g. to 10 g. per l mol. of silver halide.

3. The photographic light-sensitive material as claimed in claim 1 wherein said compound is one member selected from the group consisting of s-benzylsulfenyldithiocarboxydimethylamine, N-(s-benzylsulfenyldithiocarboxy) (sbenzylsulfenyldithiocarboxy) piperidine, l-chlorophenyl-4-(sbenzylsulfenyldithiocarboxy) piperazine, s-4-isopropylbenzylsulfenyldithiocarboxymorpholine, N-(s-B-hydroxyethylsulfenyldithiocarboxy) morpholine. N-(s-t-butylsulfenyldithiocarboxy) piperidine, N-(s-t-butylsulfenyldithiocarboxy) morpholine, s-benzylsulfenylisothiourea hydrochloride, s-furfurylsulfenylisothiourea hydrochloride, s4-isopropylbenzylsulphenylisothiourea hydrochloride and s-B-hydroxyethylsulfenylisothiourea hydrochloride.

4. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer containing a compound or salt thereof represented by the following formula,

wherein R, is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalwherein R, is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalkyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, R and R each is a member selected from the group consisting of a hydrogen atom, an alkyl group having one to five carbon atoms and an atomic group capable of forming a ring through linkage with R, and R and Q is a member selected from the group consisting of a sulfur atom and an imino group.

7. The photographic light-sensitive material as claimed in claim 6 wherein an amount of said compound is 0.05 g. to 10 g. per l mol. of silver halide.

8. The photographic light-sensitive material as claimed in claim 6 wherein said compound is one member selected from the group consisting of s-benzylsulfenyldithiocarboxydimethylamine, N-(s-benzylsulfenyldithiocarboxy) piperidine, s-4-isopropylbenzylsulfenyldithiocarboxym orpholine, N-(s-B-hydroxyethylsulfenyldithiocarboxy) morpholine, N-(s-t-butylsulfenyldithiocarboxy) piperidine, N- (s-t-butylsulfenyldithiocarboxy) morpholine, s-benzylsulfenylisothiourea hydrochloride, s-furfurylsulfenylisothiourea hydrochloride, s-4-isopropylbenzylsulphenylisothiourea hydrochloride and s-B-hydroxyethylsulfenylisothiourea hydrochloride. 7

9. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer and a photographic layer adjacent thereto containing a compound represented by the following formula,

wherein R, is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalkyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, and Q is a member selected from the group consisting of a sulfur atom and an imino group.

10. The photographic light-sensitive material as claimed in claim 9 wherein an amount of said compound is 0.05 g. to 10 g. per 1 mol. ofsilver halide.

11. A method of photographic reproduction which comprises exposing a photographic light'sensitive material comprising a support having coated thereon at least one silver halide emulsion layer and a photographic layer adjacent thereto.

one of said layers containing a compound represented by the following formula,

wherein R, is a member selected from the group consisting of an alkyl group having one to five carbon atoms, a hydroxyalkyl group having one to five carbon atoms, a tetrafurfuryl group and an aralkyl group having seven to 12 carbon atoms, R and R each is a member selected from the group consisting of a hydrogen atom, an alkyl group having one to five carbon atoms and an atomic group capable of forming a ring through linkage with R and R and Q is a member selected from the B-hydroxyethylsulfen ldithiocarboxy) morpholine.

1 The material 0 claim 9 wherein said compound 18 N-(st-butylsulfenyldithiocarboxy) morpholine. 

2. The photographic light-sensitive material as claimed in claim 1 wherein an amount of said compound is 0.05 g. to 10 g. per 1 mol. of silver halide.
 3. The photographic light-sensitive material as claimed in claim 1 wherein said compound is one member selected from the group consisting of s-benzylsulfenyldithiocarboxydimethylamine, N-(s-benzylsulfenyldithiocarboxy) piperidine, 1-chlorophenyl-4-(s-benzylsulfenyldithiocarboxy) piperazine, s-4-isopropylbenzyl-sulfenyldithiocarboxymorpholine, N-(s- Beta -hydroxyethylsulfenyldithiocarboxy) morpholine, N-(s-t-butylsulfenyldithiocarboxy) piperidine, N-(s-t-butylsulfenyldithiocarboxy) morpholine, s-benzylsulfenylisothiourea hydrochloride, s-furfurylsulfenylisothiourea hydrochloride, s-hydrochloride and s-Beta -hydroxyethylsulfenylisothiourea hydrochloride.
 4. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer containing a compound or salt thereof represented by the following formula,
 5. The photographic light-sensitive material as claimed in claim 4 an amount of said compound is 0.05 g. to 10 g. per 1 mol. of silver halide.
 6. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer and a photographic layer adjacent thereto containing a compound represented by the following formula,
 7. The photographic light-sensitive material as claimed in claim 6 wherein an amount of said compound is 0.05 g. to 10 g. per 1 mol. of silver halide.
 8. The photographic light-sensitive material as claimed in claim 6 wherein said compound is one member selected from the group consisting of s-benzylsulfenyldithiocarboxydimethylamine, N-(s-benzylsulfenyldithiocarboxy) piperidine, 1-chlorophenyl-4-(s-benzylsulfenyldithiocarboxy)piperazine, s-4-isopropylbenzylsulfenyldithiocarboxymorpholine, N-(s- Beta -hydroxyethylsulfenyldithiocarboxy) morpholine, N-(s-t-butylsulfenyldithiocarboxy) piperidine, N-(s-t-butylsulfenyldithiocarboxy) morpholine, s-benzylsulfenylisothiourea hydrochloride, s-furfurylsulfenylisothiourea hydrochloride, s-4-isopropylbenzylsulphenylisothiourea hydrochloride and s- Beta -hydroxyethylsulfenylisothiourea hydrochloride.
 9. A photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer and a photographic layer adjacent thereto containing a compound represented by the following formula,
 10. The photographic light-sensitive material as claimed in claim 9 wherein an amount of said compound is 0.05 g. to 10 g. per 1 mol. of silver halide.
 11. A method of photographic reproduction which comprises exposing a photographic light-sensitive material comprising a support having coated thereon at least one silver halide emulsion layer and a photographic layer adjacent thereto, one of said layers containing a compound represented by the following formula,
 12. The material of claim 1 wherein said compound is s-4-isopropylbenzylsulfenyldithiocarboxy-morpholine.
 13. The material of claim 1 wherein said compound is N-(s- Beta -hydroxyethylsulfenyldithiocarboxy) morpholine.
 14. The material of claiM 1 wherein said compound is N-(s-t-butylsulfenyldithiocarboxy) morpholine.
 15. The material of claim 9 wherein said compound is s-4-isopropylbenzylsulfenyldithiocarboxy-morpholine.
 16. The material of claim 9 wherein said compound is N-(s- Beta -hydroxyethylsulfenyldithiocarboxy) morpholine.
 17. The material of claim 9 wherein said compound is N-(s-t-butylsulfenyldithiocarboxy) morpholine. 